code: def _create_fake_sample(self):
      fake_sample = {
          "fieldBBs": [
              {
                  "poly_points": [
                      [1357, 322],
                      [1636, 324],
                      [1636, 402],
                      [1357, 400],
                  ],
                  "type": "field",
                  "id": "f0",
                  "isBlank": 1,
              },
              {
                  "poly_points": [
                      [1831, 352],
                      [1908, 353],
                      [1908, 427],
                      [1830, 427],
                  ],
                  "type": "blank",
                  "id": "f1",
                  "isBlank": 1,
              },
          ],
          "textBBs": [
              {
                  "poly_points": [
                      [1388, 80],
                      [2003, 82],
                      [2003, 133],
                      [1388, 132],
                  ],
                  "type": "text",
                  "id": "t0",
              },
              {
                  "poly_points": [
                      [1065, 366],
                      [1320, 366],
                      [1320, 413],
                      [1065, 412],
                  ],
                  "type": "text",
                  "id": "t1",
              },
          ],
          "imageFilename": "004173988_00005.jpg",
          "transcriptions": {
              "f0": "7/24",
              "f1": "9",
              "t0": "REGISTRY RETURN RECEIPT.",
              "t1": "Date of delivery",
          },
      }
      ann_path = osp.join(self.root.name, "naf.json")
      with open(ann_path, "w") as f:
          json.dump(fake_sample, f)
      return ann_path
  
file_path: mmocr/tests/test_datasets/test_preparers/test_parsers/test_naf_parser.py
imports: import json
  import os.path
  import tempfile
  import unittest
  from mmocr.datasets.preparers import NAFAnnParser
label_desc: Use image node_id 2 for calling the TestNAFAnnParser obj's underlying member method code with example usage: obj._create_fake_sample() and returns: ann_path